Archived posting to the Leica Users Group, 2014/07/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Howard a DNG is essentially a TIFF with some more instructions. Cheers Geoff http://www.pbase.com/hoppyman On 3 July 2014 06:41, Howard Ritter <hlritter at bex.net> wrote: > This file-size difference is intrinsic to TIFF, which interpolates a value > for all 3 colors, R-G-B, for each pixel. > > The X-Pro 1 has a 24-Mpx sensor, 8 million for each of R, G, and B (this > is simplified), each of which generates 1 byte of luminance information. So > its raw (adjective, not acronym!) file size is 1 byte x 8 Mpx x 3 > colors--to > a first approximation, 24 MB. If JPEGed for storage, it is re-expanded when > viewed. When the image is viewed or printed, software gives each R > photosite also a G and a B value by interpolation from adjacent G and B > photosites, and likewise for native G and B photosites. So the full image > you see in Photoshop should have a file size of ~72MB. TIFF is simply this > full file, with interpolated colors at each pixel. That's why it's always > generally about 3 x the size of the stripped-down raw file. Differences > seen in practice may result from compression, which can save significant > storage capacity without loss of information (unlike JPEG). There may be > some housekeeping stuff that brings your TIFF file to 4 x your raw; perhaps > the file also incorporates a separate raw image. > > I don't know how this relates to DNG, though. > > --howard > > > On Jul 2, 2014, at 1:58 PM, Ken Carney <kcarney1 at cox.net> wrote: > > > I hadn't really looked either. My X raw files are about 24-27 MB (not > sure what causes the size differential), opening to 94MB Tiff's. My Canon > 5D MkII files are roughly the same raw size, but open to 120+ MB Tiff's. > > > > Ken > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >